Python Mysql 篇

  

Python 操作 Mysql 模块的安装

linux:

    yum install MySQL-python

window:
http://files.cnblogs.com/files/wupeiqi/py-mysql-win.zip
unbuntu
  https://pypi.python.org/pypi/MySQL-python/1.2.5#downloads
  解压后pip setup.py build 如果报错 EnvironmentError: mysql_config not found
  sudo apt-get install libmysqlclient-dev
  sudo updatedb
  locate mysql_config
  mysql_config的位置为:/usr/bin/mysql_config   在mysql-python源码包下找到:setup_posix.py 文件,然后找到文件中的 mysql_config.path 将其值改为:/usr/bin/mysql_config,然后 sudo python    setup.py install ,就ok了

安装

SQL 基本使用:

1、数据库操作

show databases;
use [databasename];
create database [name];

2、数据表操作

show tables;

create table students
(
id int not null auto_increment primary key,
name char(8) not null,
sex char(4) not null,
age tinyint unsigned not null,
tel char(13) null default "-"
);
desc chen.student; #desc获取表结构

3、数据操作

insert into student(name,sex,age,tel) values("chen","man","","");

delete from student where id = 1;

update student set name = 'chen' where id =2;

select * from student;

Python MySQL API

import MySQLdb

# 连接到数据库
conn = MySQLdb.connect(host="127.0.0.1",user="root",passwd="chen27",db="chen")
cur = conn.cursor() #创建游标 #插入数据,注意mysql的占位符是%s(通过游标的方法execute插入数据)
recount = cur.execute('insert into student(name,sex,age,tel) values(%s,%s,%s,%s)',("chen27","man","","")) #提交事物
conn.commit()
# 关闭连接
cur.close #关闭游标
conn.close() # 关闭连接 print recount

批量插入数据

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='chen',db='mydb')

cur = conn.cursor()

li =[
('alex','usa'),
('sb','usa'),
]
reCount = cur.executemany('insert into UserInfo(Name,Address) values(%s,%s)',li) conn.commit()
cur.close()
conn.close() print reCount

二、删除数据

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')

cur = conn.cursor()

reCount = cur.execute('delete from UserInfo')

#conn.rollback() 回滚操作
conn.commit() cur.close()
conn.close() print reCount

三、修改数据

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')

cur = conn.cursor()

reCount = cur.execute('update UserInfo set Name = %s',('alin',))

conn.commit()
cur.close()
conn.close() print reCount

四、查数据

# ############################## fetchone/fetchmany(num)  ##############################

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
cur = conn.cursor() reCount = cur.execute('select * from UserInfo') print cur.fetchone() # 取一条 fetchall() 取所有 fetchmany(num) 指定多少条
print cur.fetchone()
cur.scroll(-1,mode='relative')
print cur.fetchone()
print cur.fetchone()
cur.scroll(0,mode='absolute')
print cur.fetchone()
print cur.fetchone() cur.close()
conn.close() print reCount # ############################## fetchall ############################## import MySQLdb conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
#cur = conn.cursor(cursorclass = MySQLdb.cursors.DictCursor)
cur = conn.cursor() reCount = cur.execute('select Name,Address from UserInfo') nRet = cur.fetchall() cur.close()
conn.close() print reCount
print nRet
for i in nRet:
print i[0],i[1]

一些参数

cursor用来执行命令的方法:

     callproc(self, procname, args):用来执行存储过程,接收的参数为存储过程名和参数列表,返回值为受影响的行数
  execute(self, query, args):执行单条sql语句,接收的参数为sql语句本身和使用的参数列表,返回值为受影响的行数
  executemany(self, query, args):执行单挑sql语句,但是重复执行参数列表里的参数,返回值为受影响的行数
  nextset(self):移动到下一个结果集 cursor用来接收返回值的方法:   fetchall(self):接收全部的返回结果行.
  fetchmany(self, size=None):接收size条返回结果行.如果size的值大于返回的结果行的数量,则会返回cursor.arraysize条数据.
  fetchone(self):返回一条结果行.
  scroll(self, value, mode='relative'):移动指针到某一行.如果mode='relative',则表示从当前所在行移动value条,如果mode='absolute',则表示从结果集的第一 行移动value条.
 
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